An experimental model of chronic severe mitral regurgitation.

Objective: To develop a minimally invasive, reproducible model of chronic severe mitral regurgitation (MR) that replicates the clinical phenotype of left atrial (LA) and left ventricular dilation and susceptibility to atrial fibrillation. Methods: Under transesophageal echocardiographic guidance, chordae tendinae were avulsed using endovascular forceps until the ratio of regurgitant jet area to LA area was ≥70%. Animals survived for an average of 8.6 ± 1.6 months (standard deviation) and imaged with monthly transthoracic echocardiography (TTE). Animals underwent baseline and preterminal magnetic resonance imaging. Terminal studies included TTE, transesophageal echocardiography, and rapid atrial pacing to test inducibility of atrial tachyarrhythmias. Results: Eight dogs underwent creation of severe MR and interval monitoring. Two were excluded-one died from acute heart failure, and the other had resolution of MR. Six dogs underwent the full experimental protocol; only one required medical management of clinical heart failure. MR remained severe over time, with a mean terminal regurgitant jet area to LA area of 71 ± 14% (standard deviation) and regurgitant fraction of 52 ± 11%. Mean LA volume increased over 130% (TTE: 163 ± 147%, P = .039; magnetic resonance imaging: 132 ± 54%, P = .011). Mean left ventricular end-diastolic volume increased by 38 ± 21% (P = .008). Inducible atrial tachyarrhythmias were seen in 4 of 6 animals at terminal surgery, and none at baseline. Conclusions: Within the 6 dogs that successfully completed the full experimental protocol, this model replicated the clinical phenotype of severe MR, which led to marked structural and electrophysiologic cardiac remodeling. This model allowed for precise measurements at repeated time points and will facilitate future studies to elucidate the mechanisms of atrial and ventricular remodeling secondary to MR and the pathophysiology of valvular atrial fibrillation.

Developing the eMedical Student (eMS)-A Pilot Project Integrating Medical Students into the Tele-ICU during the COVID-19 Pandemic and beyond.

The COVID-19 pandemic has accelerated the demand for virtual healthcare delivery and highlighted the scarcity of telehealth medical student curricula, particularly tele-critical care. In partnership with the Penn E-lert program and the Department of Anesthesiology and Critical Care, the Perelman School of Medicine (PSOM) established a tele-ICU rotation to support the care of patients diagnosed with COVID-19 in the Intensive Care Unit (ICU). The four-week course had seven elements: (1) 60 h of clinical engagement; (2) multiple-choice pretest; (3) faculty-supervised, student-led case and topic presentations; (4) faculty-led debriefing sessions; (5) evidence-based-medicine discussion forum; (6) multiple-choice post-test; and (7) final reflection. Five third- and fourth-year medical students completed 300 h of supervised clinical engagement, following 16 patients over three weeks and documenting 70 clinical interventions. Knowledge of critical care and telehealth was demonstrated through improvement between pre-test and post-test scores. Professional development was demonstrated through post-course preceptor and learner feedback. This tele-ICU rotation allowed students to gain telemedicine exposure and participate in the care of COVID patients in a safe environment.

The Weekend Effect in Hospitalized Patients: A Meta-Analysis.

BACKGROUND: The presence of a "weekend effect" (increased mortality rate during Saturday and/or Sunday admissions) for hospitalized inpatients is uncertain. PURPOSE: We performed a systematic review to examine the presence of a weekend effect on hospital inpatient mortality. DATA SOURCES: PubMed, EMBASE, SCOPUS, and Cochrane databases (January 1966-April 2013) were utilized for our search. STUDY SELECTION: We examined the mortality rate for hospital inpatients admitted during the weekend compared with those admitted during the workweek. To be included, the study had to provide discrete mortality data around the weekends (including holidays) versus weekdays, include patients who were admitted as inpatients over the weekend, and be published in English. DATA EXTRACTION: The primary outcome was all-cause weekend versus weekday mortality with subgroup analysis by personnel staffing levels, rates and times to procedures rates and delays, or illness severity. DATA SYNTHESIS: A total of 97 studies (N = 51,114,109 patients) were examined. Patients admitted on the weekends had a significantly higher overall mortality (relative risk, 1.19; 95% confidence interval, 1.14-1.23). With regard to the subgroup analyses, patients admitted on the weekends consistently had higher mortality than those admitted during the week, regardless of the levels of weekend/weekday differences in staffing, procedure rates and delays, and illness severity. CONCLUSIONS: Hospital inpatients admitted during weekends may have a higher mortality rate compared with inpatients admitted during the weekdays.